Technology at Harley

This one stumped me for quite a while. I’ve had random complaints that “webmail isn’t working” but I could never catch it in action, it always worked for me (on my desktop, laptop and even my phone). People would tell me that the webpage would say loading forever. Finally someone with a laptop who was having the problem brought it in so I could play with it. At that point I figured out it was related to Compatibility View in Internet Explorer 10.

If you add “webmail.harleyschool.org” to the list of sites to use Compatibility View or simply click on the little icon in the address bar the site displays perfectly again.

This really irritates me because Outlook Web Access (OWA) is a Microsoft product, and it doesn’t work as well as it should in any browser other than Internet Explorer and now the new version of IE won’t display it correctly without tweaks.

One of the features of our new internet connection is native IPv6 connectivity. As the IPv4 address space is exhausted and will soon be very expensive to get addresses, IPv6 needs to be on everyone’s radar. Our ten year old layer-3 core switch doesn’t support IPv6 but I was able to bring up a virtual Linux server to do the routing. Obviously this isn’t an ideal situation, but until we can get a more up-to-date router, this should work for giving all our servers v6 addresses.

Fibertech gave us a /48 block of addresses. That’s 2^(128-48) or 1,208,925,819,614,629,174,706,176 addresses! I’m hoping that’s enough. If you were to scan 1 million of our addresses every second it would take you 3 times the age of the universe to scan them all.

For a few years now I’ve been trying to get a metro-ethernet connection at school for our internet access. This year we finally managed it. We were using Time Warner’s highest bandwidth package, 50/5Mbps Wideband, but it just wasn’t enough. Their DOCSIS connections are still best-effort with no service-level agreements and that wasn’t quite good enough either.

We ended up signing a contract with Fibertech Networks for a 30/30Mbps metro-ethernet connection over fiber. They gave us a /27 block of IPv4 addresses and a /48 block of IPv6 addresses. I’ve been very happy with the whole process so far. The fiber was pulled on time (and I got to watch them do it) and the service was turned up right on schedule. There were no IP address SNAFUs like the last time with TWC and so far it’s working just as it should.

[Show as slideshow]

Jim and I playing around with the Android app…

Last weekend our email server hit the database size limit and dismounted the information store, halting all email transport and access.

Originally with Exchange 2003 Standard Edition there was a 16GB limit on the information store. This was one of the factors used to force you to upgrade to the Enterprise Edition which is ridiculously more expensive . When the database hit that size it would dismount causing all your users to start wrapping torches and sharpening pitchforks. They enabled a registry tweak to allow you 1 more GB of space to allow you to mount the store and reclaim some space by deleting old email.

With Service Pack 2 they upped the default limit to 18GB, which is the threshold we hit a few days ago, and allowed an absolute limit of up to 75GB. You can set this limit with another registry tweak.

Of course this couldn’t have happened on a weekday when I was here, it had to happen on a Saturday while I was out to lunch with the family and some friends. Figures…

I’ve been meaning to reorganize one of our servers racks for quite a while now. I have a big UPS to mount in the rack, but according to the manufacturer they recommend not mounted any servers within 12-18 inches of the transformer as the magnets inside can damage other magnetic media such as server hard drives.

In order to mount this UPS, I had to move 2 servers to made the necessary room.  Unfortunately, they were two very important server that couldn’t be arbitrarily turned off: Exchange (email) and Oracle (our student information system database).

Usually I would do something like this early in the morning before school starts, but family responsibilities now make that impossible. I ended up doing it in the morning on the first day of holiday break. Nobody was around so the timing wasn’t as important.

I wanted to mount these all in one solid block, but that 2u-sized hole in the middle was about 1/32″ too small to slide the email server into.  I still don’t really understand why it didn’t fit and was not very happy about it because I had already shut down the email server. So instead of a 5 minute move, I had to remount the rails and it turned into a 30 minute affair. It all worked out in the end though.